Drop a comment with your controller model and Windows version. I or the community will help troubleshoot.
The software acts as a centralized management platform for security hardware, offering: ZKAccess3.5 Access Control Software - ZKTeco Technology Zkaccess 5.2 Software Download
If you cannot find it, contact ZKTeco support directly. They will often send a Dropbox/Google Drive link. Drop a comment with your controller model and
: Supports managing access control data for up to 30,000 people and roughly 100 devices in standard configurations. Zkaccess 5.2 Software Download